On Tue, 24 Jul 2007, Al Viro wrote: > AFAICS, the patch below should do it for i386; instead of > using a dummy loop to tell gcc that this sucker never returns, > we do > static void __always_inline __noreturn __BUG(const char *file, int line); > containing the actual asm we want to insert and define BUG() as > __BUG(__FILE__, __LINE__). It looks safe, but I don't claim enough > experience with gcc __asm__ potential nastiness, so...
Sounds like it doesn't work: http://gcc.gnu.org/ml/gcc/2007-02/msg00107.html [The] programmer won't get optimization he wants as after inlining this as after inlining this attribute information becomes completely lost. What about __builtin_trap? It results in int 6 that might not be applicable, but adding some control over it to i386 backend is definitly an option. Honza It seems like if __BUG() is not inlined, you get the bogus noreturn does return warning. If it is inlined, then you lose the noreturn attribute and un-reachable code paths aren't eliminated. Adding __builtin_trap after the asm might be an ok fix. It will emit a spurious int 6, but that won't even be reached since the asm doesn't return, and it probably be less extra code than the loop. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
